Carbon-carbon composite components are increasingly being proposed for use in very high temperature applications. The term carbon-carbon composite should be understood in this specification and the claims to refer to a composite comprised of fibers in a crystal graphitic form of carbon in a matrix which is also graphitic but in both crystal and amorphous forms of carbon. Carbon-carbon composites of this type are well known and are discussed is handbooks such as Engineer's Guide to Composite Materials and Engineered Materials Handbook. In many cases the need exists for joining carbon-carbon composite components for such use. Low temperature joints are made with epoxy materials and intermediate temperature joints are made with silver base braze alloys. Neither of these joining processes are suitable for structures designed to perform in the 2500 F. to 3000 F. temperature range.
Efforts to join high temperature components of other materials have been reported. Apparently, successful joints of silicon carbide were made by furnace brazing and diffusion welding using compounds such as molybdenum disilicide, titanium dicilicide and silicon hexaboride. Lower temperature graphite joints have been made using chromium carbide coatings and molybdenum coatings with copper interlayers.